Armor thickness question

Hello, i always wondered whats with the armor on WWII tanks, King Tiger for example has 180mm (?) of armor at the front right?
If you compare this to modern MBT's wich have more than 800mm of armor in front (some of them) how come that they still weight less than the King Tiger?

 

It isn't 80cm thick, it's comparable to 80cm of homogenous steel. And King Tiger armor is pure steel but modern MBTs have lighter materials in their armor.

 

Back in ww2 the usual material used on armour was steel or at best reïnforced steel. Today, other materials like Kevlar and plastics are used to make good armour. Effect is thesame, yet the weight is significantly less.

 

on kevlar jackets it has a warning saying keep away from hight velocity rifle bullets and sharp objects(what a pencil)

 

Not to mention reactive armour (which actually explodes outwards, stopping incoming grenades) and anti-HEAT armour, which has ceramics in it (which is very heat-absorbant, just like ceramic tiles are also on the nose of the space shuttle).

 

Wow! Space materials on tanks! Should I move this topic to "modern tanks"section or what? This starts to go the modern tanks way, anyway.

 

For example, T-72 armor consists of layers of aluminium oxide and steel.

 

Good thing it isn't the reverse (since Ferra Oxide and Aluminium = Thermite )

Christian

 

lol :lol:

 

Thermite, is it something that burns?

 

One reason is that WWII tanks had better all-round protection. According to Richard Simpkin (if you see any of his books kill to get them) a modern tank has 45% or so of its armour by weight on the front arc alone.
They're designed for an attack covering about 60 degrees of frontal arc (Whittaker's DPV IIRC), whereas in WWII the studies of likely attack directions hadn't been done, so they put thick(ish) armour all over.

Plus we now have lighter powerplants and lighter materials for non-essential/ lower vulnerability equipment.
Oli

 

Frontal turret + hull armor is very strong
Side turret + hull armor is very strong

The back of the turret and hull are not so strong because this is where the engine is, and that needs colling so you can't place thick layers of armor there, but overall its allround protection is very good, so I don't know where you got that from.
Its true that the most armor is located at the front of turret/hull, but the sides are not weak in any aspect...

 

Didn't say weak, check out any of Simpkins' books or Rolf Hilmes' volume on post WWII tank design as translated by Simpkin (or it might be Ogorkiewicz).
Basically modern tanks are all frontal aspect protection, with moderate on the rest, WWII was medium or better all round.
In fact check out why Audtralia is replacing its Leopard 1 tanks - modern 30mm ammo will penetrate on the front.
Oli

 

I don't believe modern 30mm will penetrate the front of a Leopard1, I also don't believe that the sides of a tank are moderate, side turret armor can withstand multiply (many) hits of an RPG-7.

 

Belief does not alter reality! The Loepard was reported as usch in Jane's Defence Weekly about three years ago. And multiple hits from an RPG? Depends upon where the hits are. If they're all in the same spot then it's unlikely. Survivability is not an exact science. Like I said, read the books.
Oli

 

Don't have the books...
I rather believe practical prove more than theoretic prove...

 

armor and survivability

As a non sequitur but an interesting comment about survivability, I would offer the experience of a guy I once knew. He commanded a tank company in the 11th ACR in Vietnam. On one of his operations, one of his M48A3's (I think it was an A3) was hit by RPG-2's something like 15 times. Eight actually penetrated the engine compartment or the crew compartment. All crew members were wounded, but not so seriously that they couldn't keep fighting. The tank also remained battle-worthy.

 

yeah , but modern militaries are shy about releasing info on their tanks armour thickness.

 

Re: armor and survivability

Battle-worthy with all those holes in it?? Like the story of the Vickers Mk.VI crew in France 1940. Took a hit from a 37 I think, that went in one side of the turret, missed the crew and out the other. The gunner took his dirty socks out his kit bag, bunged the holes up with one sock each and went back to fighting!
The socks probably gave better protection than the armour - commonly known as the "Brown Paper Tank", 'cos that's all the armour was worth.
Oli

 

Just noticed this one. This is similar to the story that M113 used aluminium armour, (aluminium being lighter than steel), making it lighter than the equivalent vehicle in steel, say FV432.
But aluminium offeres only one third of the protection for the same weight. Which means that the armour on M113 is three times thicker than it would be if it was steel - same weight.
There is a slight saving, in that the three-times-thicker armour shell is now strong enough to used structurally, unlike other vehicles which have the armour fastened to a framework.
Lighter armour materials usually means "thicker" armour for the same weight but only the same effective thickness.
Weight saving is made elsewhere.
As for keeping kevlar away from pencils - nearly. Kevlar is woven fabric so small sharp objects offer no resistance to it - kevlar is useless against flechettes.
Oli